43 research outputs found
On Stability of Hyperbolic Thermoelastic Reissner-Mindlin-Timoshenko Plates
In the present article, we consider a thermoelastic plate of
Reissner-Mindlin-Timoshenko type with the hyperbolic heat conduction arising
from Cattaneo's law. In the absense of any additional mechanical dissipations,
the system is often not even strongly stable unless restricted to the
rotationally symmetric case, etc. We present a well-posedness result for the
linear problem under general mixed boundary conditions for the elastic and
thermal parts. For the case of a clamped, thermally isolated plate, we show an
exponential energy decay rate under a full damping for all elastic variables.
Restricting the problem to the rotationally symmetric case, we further prove
that a single frictional damping merely for the bending compoment is sufficient
for exponential stability. To this end, we construct a Lyapunov functional
incorporating the Bogovski\u{i} operator for irrotational vector fields which
we discuss in the appendix.Comment: 27 page
Multidimensional Thermoelasticity for Nonsimple Materials -- Well-Posedness and Long-Time Behavior
An initial-boundary value problem for the multidimensional type III
thermoelaticity for a nonsimple material with a center of symmetry is
considered. In the linear case, the well-posedness with and without
Kelvin-Voigt and/or frictional damping in the elastic part as well as the lack
of exponential stability in the elastically undamped case is proved. Further, a
frictional damping for the elastic component is shown to lead to the
exponential stability. A Cattaneo-type hyperbolic relaxation for the thermal
part is introduced and the well-posedness and uniform stability under a
nonlinear frictional damping are obtained using a compactness-uniqueness-type
argument. Additionally, a connection between the exponential stability and
exact observability for unitary -groups is established.Comment: 28 page
Global Well-Posedness and Exponential Stability for Heterogeneous Anisotropic Maxwell's Equations under a Nonlinear Boundary Feedback with Delay
We consider an initial-boundary value problem for the Maxwell's system in a
bounded domain with a linear inhomogeneous anisotropic instantaneous material
law subject to a nonlinear Silver-Muller-type boundary feedback mechanism
incorporating both an instantaneous damping and a time-localized delay effect.
By proving the maximal monotonicity property of the underlying nonlinear
generator, we establish the global well-posedness in an appropriate Hilbert
space. Further, under suitable assumptions and geometric conditions, we show
the system is exponentially stable.Comment: updated and improved versio
Boundary Stabilization of Quasilinear Maxwell Equations
We investigate an initial-boundary value problem for a quasilinear
nonhomogeneous, anisotropic Maxwell system subject to an absorbing boundary
condition of Silver & M\"uller type in a smooth, bounded, strictly star-shaped
domain of . Imposing usual smallness assumptions in addition to
standard regularity and compatibility conditions, a nonlinear stabilizability
inequality is obtained by showing nonlinear dissipativity and
observability-like estimates enhanced by an intricate regularity analysis. With
the stabilizability inequality at hand, the classic nonlinear barrier method is
employed to prove that small initial data admit unique classical solutions that
exist globally and decay to zero at an exponential rate. Our approach is based
on a recently established local well-posedness theory in a class of
-valued functions.Comment: 22 page
Long-Time Behavior of Quasilinear Thermoelastic Kirchhoff-Love Plates with Second Sound
We consider an initial-boundary-value problem for a thermoelastic Kirchhoff &
Love plate, thermally insulated and simply supported on the boundary,
incorporating rotational inertia and a quasilinear hypoelastic response, while
the heat effects are modeled using the hyperbolic Maxwell-Cattaneo-Vernotte law
giving rise to a 'second sound' effect. We study the local well-posedness of
the resulting quasilinear mixed-order hyperbolic system in a suitable solution
class of smooth functions mapping into Sobolev -spaces. Exploiting the
sole source of energy dissipation entering the system through the hyperbolic
heat flux moment, provided the initial data are small in a lower topology
(basic energy level corresponding to weak solutions), we prove a nonlinear
stabilizability estimate furnishing global existence & uniqueness and
exponential decay of classical solutions.Comment: 46 page
Representation of Classical Solutions to a Linear Wave Equation with Pure Delay
For a wave equation with pure delay, we study an inhomogeneous
initial-boundary value problem in a bounded 1D domain. Under smoothness
assumptions, we prove unique existence of classical solutions for any given
finite time horizon and give their explicit representation. Continuous
dependence on the data in a weak extrapolated norm is also shown.Comment: 11 pages, 1 figur
Exponential Decay of Quasilinear Maxwell Equations with Interior Conductivity
We consider a quasilinear nonhomogeneous, anisotropic Maxwell system in a
bounded smooth domain of with a strictly positive conductivity
subject to the boundary conditions of a perfect conductor. Under appropriate
regularity conditions, adopting a classical -Sobolev solution framework,
a nonlinear energy barrier estimate is established for local-in-time
-solutions to the Maxwell system by a proper combination of higher-order
energy and observability-type estimates under a smallness assumption on the
initial data. Technical complications due to quasilinearity, anisotropy and the
lack of solenoidality, etc., are addressed. Finally, provided the initial data
are small, the barrier method is applied to prove that local solutions exist
globally and exhibit an exponential decay rate.Comment: 24 page